Crane



2 Sheets-l-Sheet 1. L. ATWOOD.

CRANE (No Model.)

Patented May so, 1893.

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- L. ATWOOD.

CRANE.

No. 498,605. Patented May l30, 1893.

Q, A w K X :mloo o m gw w/MIMM Y M M s ,fg .i f. @GNN n SNR V"'lUNrrn Stearns LEONARD A'IWOOD, OF PHILADELPHIA, PENNSYLVANIA.

CRANE.

SPECIFICATION forming part of Letters Patent No. 498,605, dated May 30, 1893.

Application filed March 20, 1890. Serial Noe 344,665. (No model.)

To a/ZZ'whom/ t may concern,.-

Be it known that I, LEONARD A'rwooD, a citizen of the United States, and a resident of Philadelphia, Pennsylvania, have invented certain Improvements in Cranes, of which the following is a specification.

My invention relates to certain improvements in hydraulic cranes and has for its object the construction of a crane which may be operated by a pump contained within its base and forming a self contained structure; the pump being driven preferably by an independent motor, such as an electric motor, as more fully set forth hereinafter.

In the accompanying drawings:-Figure l is an elevation of my improved crane, a portion of the standard being cut away. Fig. 2, is a vertical section of the same on the line 3 4, Fig. l. Fig. 3, is a sectional plan view on the line l-2, Fig. 2, on a somewhat larger scale. Fig. 4, is a vertical section on the line 5-6, Fig. 3. Fig. 5, is a vertical section on the line 7--S, Fig. 3. Figs. 6 and 7, are views showing the controlling valve in different positions.

A is the base of the crane to which is secured a vertical hollow standard B having at its upper end a suitable cap B by which it may be secured to the root` or supporting beam of a building; the hollow standard being utilized as a reservoir for the iluid by which the crane is operated.

Secured to the standard Bis a piston b provided with suitable packing and tting over the piston and the standard B is a movable cylinder D preferably open at its lower endand suitably packed at its upper end to prevent the escape of fluid between the head of the cylinder and the standard. On the exterior of the cylinder are pins d, CZ, on which arev mounted tie bars E, E, secured at their upper and lower ends respectively to collars E', E2

adapted to slide upon the standard B above and below the cylinder; secured to the collar E', as shown in Fig. l, is a horizontal crane arm F; the object of this construction being to prevent the binding of the cylinder upon mounted a shaft G carrying a piston H provided with radial slots h for the sliding piston blades g. The pump is driven in the present instance from an electric motor, the shaft I of which is connected tothe shaftGof the pump, through the pinion z' and gear wheel i. By using an electric motor to drive the pump I dispense entirely with line shafting. and with piping, using simply the vordinary current conducting wires.

The inletj for the pump connects with the interior of the standard B which forms a reservoir from which the pump is supplied, and the outlet passage k from the pump communicates with a transverse passage. Zo in the base A. The fluid from the pump passes out through the passage k, into and through the passages lo', Z, Z, through the ports of the regulating valve m, and thence through the passage m to the vertical pipe n which communicates with the space in the cylinder bctween the head and the piston, so that the fluid as it is forced by the pump from the reservoir will pass into the cylinder and raise it when the controlling valve m is in the position shown in. Fig. 5.

The controlling valve m is provided with a suitable operating handle m2 and when it is desired to lower the crane arm and cylinder the valve is turned to the position shown in Fig. 7, the iiuid passing out through the pipe| n, the passage m', the ports of the valve m, the passage-p, the pipe p to the opposite side of the base A; through the passages q, q to the passage j and thence into the reservoirB.

To -maintain the cylinder in an elevated position the controlling valvem is turned Vto the position shown in Fig. 6, confining the fluid in the cylinder, the pipe n and the passage n. The fluid as it is forced by the pump passing through the passage Zo, the passages k', Z, p, p and q to the inlet side of the pump, so that the motor can be run continuously while the load is suspen ded. When the pressure in the pump exceeds the pressure to lift the load, or the valve m has been so turned as to cut otE the passage Z', I provide a by-pass, preferably by a pipe s communicating at its opposite ends with the passages 7c and q and having therein a valve S-norma'lly closed by the pressure of a spring s of sufficient strength to keep the valve closed under ordinary pressures, but

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so arranged that when the pressure exceeds a certain predetermined limit the Valve will open and the excess of iuid passes through the pipe s to the passage q which communicates with the opposite side of the pump cylinder.

In some instances the reservoir may be independent of the standard, but is preferably in close proximity to the crane or situated on the crane, as shown for instance by dotted lines in Fig. 2.

I claim as my invention- 1. The combination of the Iixed standard, a piston t-hereon, a movable cylinder mounted on said standard, sliding collars on the standard above and below the cylinder, vertical tie bars connecting the cylinder to the collars,a crane arm projecting from the upper collar, and a supporting strut for said crane arm carie by the lower collar, substantially as speci- 2. The combination in a crane, of the standard, a piston thereon, a cylinder adapted to slide on said standard and piston, centrally located pins on said cylinder, vertical bars E E on said pins, collars E E2 also connected to said tie bars, with a crane arm carried by the collars, substantially as specified.

3. The combination of the base, the pump therein, a standard, a reservoir therein, a pis- 3o ton secured to the standard, an open ended cylinder sliding on said piston, guiding collars connected to the cylinder and adapted to slide upon the standard, and a pipe extending within the standard and communicating 35 with the pump and with the interior of the cylinder ai; a point above the piston,substan tially as specified. i

4. The combination of the base A, a reservoir B, a cylinder D, a rotary pump in said 4o base, passage j forming communication between the reservoir and the pump, passages 7c, 7c', Z, Z', and m', and a pipe n, forming a communication between the pump and the cylinder D, a controlling valve m, and a by- 45 pass p, communicating with the passage q, leading to the inlet side of the pump, substantially as specied.

In testimony whereof I have signed my name to this specification inthe presence of 5o two subscribing Witnesses.

LEONARD ATWOOD. Witnesses:

HENRY HowsoN, HARRY SMITH. 

